This invention is particularly well suited for multiple ply tires, especially tires used on racing vehicles where the tires are individually tailored to the specific characteristics of the car such as its weight and speed. The tires of racing vehicles play an important role in winning races. The designers of such tires strive to produce the most efficient tire for the particular vehicle involved. Translated to actual performance, this means, for example, that in races like the Indianapolis 500, each tire of the vehicle is individually designed and differs from the other tires. The most efficient tire is generally thought of as having the best characteristics of, for example, size, weight, load-carrying capacity, and operating speed requirements. It has been found that the most efficient tire is produced by providing carcass plies and cord reinforcements which equally share both tension and shear stresses. The invention is directed to such a tire.
Briefly stated, the invention is in a tire comprising a plurality of carcass plies surrounded by a tread and sidewalls terminating at a pair of beads. The carcass plies are each characterized by (I) a higher end count per inch of reinforcement cords than of the next adjacent carcass ply closer the tread, (II) a smaller gauge of rubbery material than that of the next adjacent carcass ply closer the tread, and (III) lower reinforcement cord angles, measured relative to the centerplane of the tire, than those of the next adjacent carcass ply closer the tread, such that the cords of the carcass plies are uniformly stressed when the tire is mounted on a wheel rim and inflated to the normal inflation pressure recommended by the manufacturer of the tire.